In the very extensive second chapter of the “Transcendental Dialectic” Kant turns his attention to the second source of dialectical illusion of pure reason: the antinomies. Antinomies are contradictory views that are both, at least in appearance, legitimate and reasonable views held with good bases. Kant writes that “just as the paralogisms of pure reason laid the basis for a dialectical psychology, so will the antinomy of pure reason put before us the transcendental principles of a supposed pure (rational) cosmology” (444). Kant will show that this rational cosmology is just as empty as rational psychology turned out to be.

Each antinomy is two-sided. There is the thesis, which presents a positive account that the world is some particular way, and then there is its antithesis, which always claims that the world is the opposite way. The four antinomies are:

1. The world has a beginning in time and is bounded in space (thesis) and the world does not have a beginning in time and is endless in space (antithesis).

2. The world is composed of simple, atomic parts (thesis) and the world is not composed of simple parts but rather is endlessly composite (antithesis).

3. Things can be caused through free action (thesis), and nothing is caused by freedom but is instead totally determined by natural law (antithesis).